1. Field of the Invention
This invention relates to the art of automatic truck bed covers as for use with the truck bed of a pickup truck where the cover when closed serves to protect the contents of the truck bed from inclement weather, as well as serves as a security means to protect the contents from vandals and thieves. Of course, this invention is likewise usable with larger truck beds, such as dump trucks and open top trailers.
2. Description of the Prior Art
The Thorpe U.S. Pat. No. 3,774,958 shows a conventional dump truck having a sheet metal cover which is wound upon a cylindrical member which is motor-driven for opening and closing the cover. The opposite guide members for the stainless steel cover have a sinusoidal configuration to provide lateral strength to the sheet metal member.
The Penner U.S. Pat. No. 4,046,416 describes an open top truck body with a flexible cover or tarpaulin that is wound on the surface of a transverse longitudinal roller assembly, similar to a roller blind mechanism. An endless chain is journaled around front and rear sprockets. A source of motor power is connected to the sprockets so that movement of the chain will cause movement of the mounting plates that cause the flexible cover to move between its open and its closed position.
The Marvin et al U.S. Pat. No. 4,210,361 describes a sliding cover assembly for open body trucks, such as a pickup truck. The cover is a rigid cover formed of a sheet of corrugated material. There are rollers that are mounted on the opposite side edges of the corrugated cover to bear against the interior vertical wall of the track. There is a transverse shaft that has a coil spring that serves to provide torsional forces necessary to wind the slide cover thereon. In other words, this is not a motor-driven cover, but one that is manually open and closed.
The Campbell U.S. Pat. No. 4,252,362 shows a pickup truck bed cover a multi-channeled track working in combination with the pickup bed cover. The canopy of the cover comprises a double-layered sheet of fabric, such as canvas, heavy plastic, or the like, that is housed on a reel. The canopy includes a plurality of transversely extending guide members that take the form of rigid rods on the ends of which are mounted rollers. There is a hand lever and rack and pawl for applying mechanical force for winding the cover onto the reel. This is not a motor-operated system, but rather a manual system.
The German Pat. No. 2,594,910 shows a roll-up type vehicle top cover using a tarpaulin. A roller is mounted at the front end of the truck for supporting the cover, and there are tracks along the top edges of the side walls of the truck body in which the tarpaulin is supported. Take-up spools or sheaves are mounted at the rear of the trailer, and they are keyed to a common shaft which may be revolved by means of a crank engaging the shaft. This is another cover that is not motor operated.
The Albrecht et al U.S. Pat. No. 4,199,188 shows rigid covers for the open top of a truck body, but there is no flexible cover that is motor-operated as in the present invention.